I have a model/table with a json column in it as follows
t.json :options, default: {}
The column can contain many keys within it, something like this
options = {"details" : {key1: "Value1", key2: "Value2"}}
I want to set and get these values easily. So i have made getters and setters for the same.
def key1
options['details']&.[]('key1')
end
def key1=(value)
options['details'] ||= {}
options['details']['key1'] ||=0
options['details']['key1'] += value
end
But this just adds lines to my code, and it does not scale when more details are added. Can you please suggest a clean and neat way of doing this?
Use dynamic method creation:
options['details'].default_proc = ->(_,_) {{}}
ALLOWED_KEYS = %i[key1 key2 key3]
ALLOWED_KEYS.each do |key|
define_method key do
options['details'][key] if options['details'].key?(key)
end
define_method "#{key}=" do |value|
(options['details'][key] ||= 0) += value
end
end
You can just pass the key as a parameter as well right?
def get_key key=:key1
options['details']&.[](key)
end
def set_key= value, key=:key1
options['details'] ||= {}
options['details'][key] ||=0
options['details'][key] += value
end
Simple & Short
Depending on re-usability you can choose different options. The short option is to simply define the methods using a loop in combination with #define_method.
class SomeModel < ApplicationRecord
option_accessors = ['key1', 'key2']
option_accessors.map(&:to_s).each do |accessor_name|
# ^ in case you provide symbols in option_accessors
# this can be left out if know this is not the case
define_method accessor_name do
options.dig('details', accessor_name)
end
define_method "#{accessor_name}=" do |value|
details = options['details'] ||= {}
details[accessor_name] ||= 0
details[accessor_name] += value
end
end
end
Writing a Module
Alternatively you could write a module that provide the above as helpers. A simple module could look something like this:
# app/model_helpers/option_details_attribute_accessors.rb
module OptionDetailsAttributeAccessors
def option_details_attr_reader(*accessors)
accessors.map(&:to_s).each do |accessor|
define_method accessor do
options.dig('details', accessor)
end
end
end
def option_details_attr_writer(*accessors)
accessors.map(&:to_s).each do |accessor|
define_method "#{accessor}=" do |value|
details = options['details'] ||= {}
details[accessor] ||= 0
details[accessor] += value
end
end
end
def option_details_attr_accessor(*accessors)
option_details_attr_reader(*accessors)
option_details_attr_writer(*accessors)
end
end
Now you can simply extend your class with these helpers and easily add readers/writers.
class SomeModel < ApplicationRecord
extend OptionDetailsAttributeAccessors
option_details_attr_accessor :key1, :key2
end
If anything is unclear simply ask away in the comments.
Related
I would like to make a string to become an attribute:
Model:
Author
attr_accessible :book1, book2, book3 etc...
I would like to retrieve 20 books in a lesser command
def do_something
self.book1
self.book2
self.book3
....
end
This is a solution I came up with but how can I make the string become an attribute so I could retrieve the data.
def do_something
count = 0
10.times do
self."book#{count += 1}"
end
end
This will work:
def do_something
count = 0
10.times do
self.send("book#{count += 1}")
end
end
Also try this, it's simpler and it should work as well: self[:book1] or self['book1']
BTW this is weird design. Consider using array of books instead:
attr_accessible :books
...
self.books.each { |book| puts book }
self.books[0] # etc.
You can use eval.
10.times do
eval("self.book#{count} = count}")
end
So I have a form where users can input a price. I'm trying to make a before_validation that normalizes the data, clipping the $ if the user puts it.
before_validation do
unless self.price.blank? then self.price= self.price.to_s.gsub(/\D/, '').to_i end
end
If user inputs $50 This code is giving me 0. If user inputs 50$ this code gives me 50. I think since the data type is integer that rails is running .to_i prior to my before_validation and clipping everything after the $. This same code works fine if the data type is a string.
Anyone have a solution that will let me keep the integer datatype?
One way is to override the mechanism on the model that sets the price, like this:
def price=(val)
write_attribute :price, val.to_s.gsub(/\D/, '').to_i
end
So when you do #model.price = whatever, it will go to this method instead of the rails default attribute writer. Then you can convert the number and use write_attribute to do the actual writing (you have to do it this way because the standard price= is now this method!).
I like this method best, but for reference another way to do it is in your controller before assigning it to the model. The parameter comes in as a string, but the model is converting that string to a number, so work with the parameter directly. Something like this (just adapt it to your controller code):
def create
#model = Model.new(params[:model])
#model.price = params[:model][:price].gsub(/\D/, '').to_i
#model.save
end
For either solution, remove that before_validation.
I would define a virtual attribute and do my manipulation there allowing you to format and modify both the getter and setter at will:
class Model < ActiveRecord::Base
def foo_price=(price)
self.price = price... #=> Mods to string here
end
def foo_price
"$#{price}"
end
You also might want to note that:
"$50.00".gsub(/\D/, '').to_i #=> 5000
My soluction
colum price type decimal
t.decimal :price, precision: 12, scale: 6
# app/concern/sanitize_fields.rb
module SanitizeFields
extend ActiveSupport::Concern
def clear_decimal(field)
return (field.to_s.gsub(/[^\d]/, '').to_d / 100.to_d) unless field.blank?
end
def clear_integer(field)
field.to_s.strip.gsub(/[^\d]/, '') unless field.blank?
end
# module ClassMethods
# def filter(filtering_params)
# results = self.where(nil)
# filtering_params.each do |key, value|
# results = results.public_send(key, value) if value.present?
# end
# results
# end
#
# #use
# #def index
# # #products = Product.filter(params.slice(:status, :location, :starts_with))
# #end
#
# end
end
#app/controllers/products_controller.rb
include SanitizeFields
params[:product][:price] = clear_decimal(params[:product][:price])
I have a model that use both: Carrierwave for store photos, and PaperTrail for versioning.
I also configured Carrierwave for store diferent files when updates (That's because I want to version the photos) with config.remove_previously_stored_files_after_update = false
The problem is that PaperTrail try to store the whole Ruby Object from the photo (CarrierWave Uploader) instead of simply a string (that would be its url)
(version table, column object)
---
first_name: Foo
last_name: Bar
photo: !ruby/object:PhotoUploader
model: !ruby/object:Bla
attributes:
id: 2
first_name: Foo1
segundo_nombre: 'Bar1'
........
How can I fix this to store a simple string in the photo version?
You can override item_before_change on your versioned model so you don't call the uploader accesor directly and use write_attribute instead. Alternatively, since you might want to do that for several models, you can monkey-patch the method directly, like this:
module PaperTrail
module Model
module InstanceMethods
private
def item_before_change
previous = self.dup
# `dup` clears timestamps so we add them back.
all_timestamp_attributes.each do |column|
previous[column] = send(column) if respond_to?(column) && !send(column).nil?
end
previous.tap do |prev|
prev.id = id
changed_attributes.each do |attr, before|
if defined?(CarrierWave::Uploader::Base) && before.is_a?(CarrierWave::Uploader::Base)
prev.send(:write_attribute, attr, before.url && File.basename(before.url))
else
prev[attr] = before
end
end
end
end
end
end
end
Not sure if it's the best solution, but it seems to work.
Adding #beardedd's comment as an answer because I think this is a better way to handle the problem.
Name your database columns something like picture_filename and then in your model mount the uploader using:
class User < ActiveRecord::Base
has_paper_trail
mount_uploader :picture, PictureUploader, mount_on: :picture_filename
end
You still use the user.picture.url attribute to access your model but PaperTrail will store revisions under picture_filename.
Here is a bit updated version of monkeypatch from #rabusmar, I use it for rails 4.2.0 and paper_trail 4.0.0.beta2, in /config/initializers/paper_trail.rb.
The second method override is required if you use optional object_changes column for versions. It works in a bit strange way for carrierwave + fog if you override filename in uploader, old value will be from cloud and new one from local filename, but in my case it's ok.
Also I have not checked if it works correctly when you restore old version.
module PaperTrail
module Model
module InstanceMethods
private
# override to keep only basename for carrierwave attributes in object hash
def item_before_change
previous = self.dup
# `dup` clears timestamps so we add them back.
all_timestamp_attributes.each do |column|
if self.class.column_names.include?(column.to_s) and not send("#{column}_was").nil?
previous[column] = send("#{column}_was")
end
end
enums = previous.respond_to?(:defined_enums) ? previous.defined_enums : {}
previous.tap do |prev|
prev.id = id # `dup` clears the `id` so we add that back
changed_attributes.select { |k,v| self.class.column_names.include?(k) }.each do |attr, before|
if defined?(CarrierWave::Uploader::Base) && before.is_a?(CarrierWave::Uploader::Base)
prev.send(:write_attribute, attr, before.url && File.basename(before.url))
else
before = enums[attr][before] if enums[attr]
prev[attr] = before
end
end
end
end
# override to keep only basename for carrierwave attributes in object_changes hash
def changes_for_paper_trail
_changes = changes.delete_if { |k,v| !notably_changed.include?(k) }
if PaperTrail.serialized_attributes?
self.class.serialize_attribute_changes(_changes)
end
if defined?(CarrierWave::Uploader::Base)
Hash[
_changes.to_hash.map do |k, values|
[k, values.map { |value| value.is_a?(CarrierWave::Uploader::Base) ? value.url && File.basename(value.url) : value }]
end
]
else
_changes.to_hash
end
end
end
end
end
This is what actually functions for me, put this on config/initializers/paper_trail/.rb
module PaperTrail
module Reifier
class << self
def reify_attributes(model, version, attrs)
enums = model.class.respond_to?(:defined_enums) ? model.class.defined_enums : {}
AttributeSerializers::ObjectAttribute.new(model.class).deserialize(attrs)
attrs.each do |k, v|
is_enum_without_type_caster = ::ActiveRecord::VERSION::MAJOR < 5 && enums.key?(k)
if model.send("#{k}").is_a?(CarrierWave::Uploader::Base)
if v.present?
model.send("remote_#{k}_url=", v["#{k}"][:url])
model.send("#{k}").recreate_versions!
else
model.send("remove_#{k}!")
end
else
if model.has_attribute?(k) && !is_enum_without_type_caster
model[k.to_sym] = v
elsif model.respond_to?("#{k}=")
model.send("#{k}=", v)
elsif version.logger
version.logger.warn(
"Attribute #{k} does not exist on #{version.item_type} (Version id: #{version.id})."
)
end
end
end
end
end
end
end
This overrides the reify method to work on S3 + heroku
For uploaders to keep old files from updated or deleted records do this in the uploader
configure do |config|
config.remove_previously_stored_files_after_update = false
end
def remove!
true
end
Then make up some routine to clear old files from time to time, good luck
I want to add to the previous answers the following:
It can happen that you upload different files with the same name, and this may overwrite your previous file, so you won't be able to restore the old one.
You may use a timestamp in file names or create random and unique filenames for all versioned files.
Update
This doesn't seem to work in all edge cases for me, when assigning more than a single file to the same object within a single request request.
I'm using this right now:
def filename
[#cache_id, original_filename].join('-') if original_filename.present?
end
This seems to work, as the #cache_id is generated for each and every upload again (which isn't the case as it seems for the ideas provided in the links above).
#Sjors Provoost
We also need to override pt_recordable_object method in PaperTrail::Model::InstanceMethods module
def pt_recordable_object
attr = attributes_before_change
object_attrs = object_attrs_for_paper_trail(attr)
hash = Hash[
object_attrs.to_hash.map do |k, value|
[k, value.is_a?(CarrierWave::Uploader::Base) ? value.url && File.basename(value.url) : value ]
end
]
if self.class.paper_trail_version_class.object_col_is_json?
hash
else
PaperTrail.serializer.dump(hash)
end
end
What's the best Ruby/Rails way to allow users to use decimals or commas when entering a number into a form? In other words, I would like the user be able to enter 2,000.99 and not get 2.00 in my database.
Is there a best practice for this?
Does gsub work with floats or bigintegers? Or does rails automatically cut the number off at the , when entering floats or ints into a form? I tried using self.price.gsub(",", "") but get "undefined method `gsub' for 8:Fixnum" where 8 is whatever number I entered in the form.
I had a similar problem trying to use localized content inside forms. Localizing output is relatively simple using ActionView::Helpers::NumberHelper built-in methods, but parsing localized input it is not supported by ActiveRecord.
This is my solution, please, tell me if I'm doing anything wrong. It seems to me too simple to be the right solution. Thanks! :)
First of all, let's add a method to String.
class String
def to_delocalized_decimal
delimiter = I18n::t('number.format.delimiter')
separator = I18n::t('number.format.separator')
self.gsub(/[#{delimiter}#{separator}]/, delimiter => '', separator => '.')
end
end
Then let's add a class method to ActiveRecord::Base
class ActiveRecord::Base
def self.attr_localized(*fields)
fields.each do |field|
define_method("#{field}=") do |value|
self[field] = value.is_a?(String) ? value.to_delocalized_decimal : value
end
end
end
end
Finally, let's declare what fields should have an input localized.
class Article < ActiveRecord::Base
attr_localized :price
end
Now, in your form you can enter "1.936,27" and ActiveRecord will not raise errors on invalid number, because it becomes 1936.27.
Here's some code I copied from Greg Brown (author of Ruby Best Practices) a few years back. In your model, you identify which items are "humanized".
class LineItem < ActiveRecord::Base
humanized_integer_accessor :quantity
humanized_money_accessor :price
end
In your view templates, you need to reference the humanized fields:
= form_for #line_item do |f|
Price:
= f.text_field :price_humanized
This is driven by the following:
class ActiveRecord::Base
def self.humanized_integer_accessor(*fields)
fields.each do |f|
define_method("#{f}_humanized") do
val = read_attribute(f)
val ? val.to_i.with_commas : nil
end
define_method("#{f}_humanized=") do |e|
write_attribute(f,e.to_s.delete(","))
end
end
end
def self.humanized_float_accessor(*fields)
fields.each do |f|
define_method("#{f}_humanized") do
val = read_attribute(f)
val ? val.to_f.with_commas : nil
end
define_method("#{f}_humanized=") do |e|
write_attribute(f,e.to_s.delete(","))
end
end
end
def self.humanized_money_accessor(*fields)
fields.each do |f|
define_method("#{f}_humanized") do
val = read_attribute(f)
val ? ("$" + val.to_f.with_commas) : nil
end
define_method("#{f}_humanized=") do |e|
write_attribute(f,e.to_s.delete(",$"))
end
end
end
end
You can try stripping out the commas before_validation or before_save
Oops, you want to do that on the text field before it gets converted. You can use a virtual attribute:
def price=(price)
price = price.gsub(",", "")
self[:price] = price # or perhaps price.to_f
end
Take a look at the i18n_alchemy gem for date & number parsing and localization.
I18nAlchemy aims to handle date, time and number parsing, based on current I18n locale format. The main idea is to have ORMs, such as ActiveRecord for now, to automatically accept dates/numbers given in the current locale format, and return these values localized as well.
I have written following code in my project. This solved all of my problems.
config/initializers/decimal_with_comma.rb
# frozen_string_literal: true
module ActiveRecord
module Type
class Decimal
private
alias_method :cast_value_without_comma_separator, :cast_value
def cast_value(value)
value = value.gsub(',', '') if value.is_a?(::String)
cast_value_without_comma_separator(value)
end
end
class Float
private
alias_method :cast_value_without_comma_separator, :cast_value
def cast_value(value)
value = value.gsub(',', '') if value.is_a?(::String)
cast_value_without_comma_separator(value)
end
end
class Integer
private
alias_method :cast_value_without_comma_separator, :cast_value
def cast_value(value)
value = value.gsub(',', '') if value.is_a?(::String)
cast_value_without_comma_separator(value)
end
end
end
end
module ActiveModel
module Validations
class NumericalityValidator
protected
def parse_raw_value_as_a_number(raw_value)
raw_value = raw_value.gsub(',', '') if raw_value.is_a?(::String)
Kernel.Float(raw_value) if raw_value !~ /\A0[xX]/
end
end
end
end
I was unable to implement the earlier def price=(price) virtual attribute suggestion because the method seems to call itself recursively.
I ended up removing the comma from the attributes hash, since as you suspect ActiveRecord seems to truncate input with commas that gets slotted into DECIMAL fields.
In my model:
before_validation :remove_comma
def remove_comma
#attributes["current_balance"].gsub!(',', '') # current_balance here corresponds to the text field input in the form view
logger.debug "WAS COMMA REMOVED? ==> #{self.current_balance}"
end
Here's something simple that makes sure that number input is read correctly. The output will still be with a point instead of a comma. That's not beautiful, but at least not critical in some cases.
It requires one method call in the controller where you want to enable the comma delimiter. Maybe not perfect in terms of MVC but pretty simple, e.g.:
class ProductsController < ApplicationController
def create
# correct the comma separation:
allow_comma(params[:product][:gross_price])
#product = Product.new(params[:product])
if #product.save
redirect_to #product, :notice => 'Product was successfully created.'
else
render :action => "new"
end
end
end
The idea is to modify the parameter string, e.g.:
class ApplicationController < ActionController::Base
def allow_comma(number_string)
number_string.sub!(".", "").sub!(",", ".")
end
end
You can try this:
def price=(val)
val = val.gsub(',', '')
super
end
i have created a LocalizedString custom data type for storing / displaying translations using mongo_mapper.
This works for one field but as soon as i introduce another field they get written over each and display only one value for both fields. The to_mongo and from_mongo seem to be not workings properly. Please can any one help with this ? her is the code :
class LocalizedString
attr_accessor :translations
def self.from_mongo(value)
puts self.inspect
#translations ||= if value.is_a?(Hash)
value
elsif value.nil?
{}
else
{ I18n.locale.to_s => value }
end
#translations[I18n.locale.to_s]
end
def self.to_mongo(value)
puts self.inspect
if value.is_a?(Hash)
#translations = value
else
#translations[I18n.locale.to_s] = value
end
#translations
end
end
Thank alot
Rick
The problem is that from within your [to|from]_mongo methods, #translations refers to a class variable, not the instance variable you expect. So what's happening is that each time from_mongo is called, it overwrites the value.
A fixed version would be something like this:
class LocalizedString
attr_accessor :translations
def initialize( translations = {} )
#translations = translations
end
def self.from_mongo(value)
if value.is_a?(Hash)
LocalizedString.new(value)
elsif value.nil?
LocalizedString.new()
else
LocalizedString.new( { I18n.locale.to_s => value })
end
end
def self.to_mongo(value)
value.translations if value.present?
end
end
I found that jared's response didn't work for me -- I would get that translations was not found when using LocalizedString in an EmbeddedDocument.
I would get a similar problem on rick's solution where translations was nil when using embedded documents. To get a working solution, I took Rick's solution, changed the translation variable to be an instance variable so it wouldn't be overwritten for each new field that used LocalizedString, and then added a check to make sure translations wasn't nil (and create a new Hash if it was).
Of all the LocalizedString solutions floating around, this is the first time I've been able to get it working on EmbeddedDocuments and without the overwritting problem -- there still may be other issues! :)
class LocalizedString
attr_accessor :translations
def self.from_mongo(value)
puts self.inspect
translations ||= if value.is_a?(Hash)
value
elsif value.nil?
{}
else
{ I18n.locale.to_s => value }
end
translations[I18n.locale.to_s]
end
def self.to_mongo(value)
puts self.inspect
if value.is_a?(Hash)
translations = value
else
if translations.nil?
translations = Hash.new()
end
translations[I18n.locale.to_s] = value
end
translations
end
end
I found this post: which was very helpful. He extended HashWithIndifferentAccess to work as a LocalizedString. The only thing I didn't like about it was having to explicly specify the locale when setting it each time -- I wanted it to work more like a string. of course, you can't overload the = operator (at least I don't think you can) so I used <<, and added a to_s method that would output the string of the current locale....
class LocalizedString < HashWithIndifferentAccess
def self.from_mongo(value)
LocalizedString.new(value || {})
end
def available_locales
symbolize_keys.keys
end
def to_s
self[I18n.locale]
end
def in_current_locale=(value)
self[I18n.locale] = value
end
def << (value)
self[I18n.locale] = value
end
end
and then I have a class like:
class SimpleModel
include MongoMapper::Document
key :test, LocalizedString
end
and can do things like
I18n.locale = :en
a = SimpleModel.new
a.test << "English"
I18n.locale = :de
a.test << "German"
puts a.test # access the translation for the current locale
I18n.locale = :en
puts a.test # access the translation for the current locale
puts a.test[:de] # access a translation explicitly
puts a.test[:en]
puts a.test.inspect
and get
German
English
German
English
{"en"=>"English", "de"=>"German"}
so there we go -- this one actually seems to work for me. Comments welcome, and hope this helps someone!